Hurts like you can't believe. And if the ball hits you in a fleshy spot...well the bruise is spectacular. Oh, and this is a "squishy" ball, you can pinch it between your fingers. If you get hit with a "Doubles ball"...in that case, the kid in the video would be in the hospital. The ball is as hard as a rock, you can't compress it even if you stand on it.